Every year over 12,000 children will be diagnosed with cancer in the United States and distressing symptoms, such as pain, fatigue, and nausea, are experienced by the majority of these children across all cancer diagnoses. Suboptimal pain and symptom management has the potential for both immediate and long-term effects on children?s physical, social, and emotional functioning. The transition to outpatient care has resulted in a lack of systematic symptom assessment in children undergoing cancer treatment, which results in limited data for healthcare providers regarding children?s symptom experience in the home setting. In addition, current programs targeting pain in children in the home setting are largely limited to assessment tools and do not use patient-reported outcomes or capitalize on the ability of technology to deliver evidence-based pain management skills. Based upon this gap in the literature, we developed a web-based pain and symptom management intervention (Pain Buddy) that incorporates validated patient-reported measures of pain and symptoms in children with cancer, uses an electronic server to deliver child-reported symptom data in real time to healthcare providers, incorporates symptom alert algorithms to notify providers when a child has reported clinically significant symptoms, and teaches children empirically-supported cognitive and behavioral skills for pain management. A small pilot trial successfully demonstrated positive effects of Pain Buddy on pain severity in children undergoing primarily outpatient cancer treatment. The proposed randomized trial of two children?s cancer centers will examine the efficacy of Pain Buddy on decreasing symptom severity and improving quality of life in children with cancer. The primary aim of the study is to determine if Pain Buddy is more effective than attention control in reducing pain severity among children ages 8-18 years old undergoing outpatient cancer treatment. Secondary aims of the study are to: 1) Examine the impact of Pain Buddy on symptom-related distress, health-related quality of life, child functional status, and child and parent satisfaction with treatment experience; and 2) Identify baseline characteristics of children (anxiety, pain catastrophizing) and parents (stress, attitudes regarding analgesic use for children) that may moderate/mediate treatment outcomes. This project paves the way to establish effectiveness of Pain Buddy and ultimately transform care to improve the quality of life of tens of thousands of children suffering from cancer each year.